package com.practices2.util;

import java.util.Calendar;
import java.util.Date;
import java.util.HashSet;
import java.util.Random;
import java.util.Set;

public class RandomUtils {
	private static final String ASC_II = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";
	private static Random Global_Random = new Random();

	public static char nextChar() {
		return "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz".charAt(Global_Random.nextInt("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz".length()));
	}

	public static String nextString(int number) {
		StringBuffer buf = new StringBuffer();
		for (int j = 0; j < number; j++) {
			buf.append(nextChar());
		}
		return buf.toString();
	}

	public static int nextInt() {
		return Global_Random.nextInt();
	}

	public static int nextInt(int n) {
		return Global_Random.nextInt(n);
	}

	public static int nextInt(int min, int max) {
		if (max < min) {
			int data = min;
			max = data;
			min = max;
		}
		int data;
		do
			data = Global_Random.nextInt() % max;
		while ((data < min) || (data > max));
		return data;
	}

	public static Integer[] nextCombine(int m, int n) {
		Set buf = new HashSet();

		while (buf.size() <= n) {
			buf.add(Integer.valueOf(new Random().nextInt(m)));
		}

		return (Integer[]) buf.toArray(new Integer[buf.size()]);
	}

	/**
	 * 生成随即密码
	 * 
	 * @param pwd_len
	 *            生成的密码的总长度
	 * @return 密码的字符串
	 */
	public static String genRandomNum(int pwd_len) {
		// 35是因为数组是从0开始的，26个字母+10个数字
		final int maxNum = 36;
		int i; // 生成的随机数
		int count = 0; // 生成的密码的长度
		char[] str = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8',
				'9' };

		StringBuffer pwd = new StringBuffer("");
		Random r = new Random();
		while (count < pwd_len) {
			// 生成随机数，取绝对值，防止生成负数，

			i = Math.abs(r.nextInt(maxNum)); // 生成的数最大为36-1
			if (i >= 0 && i < str.length) {
				pwd.append(str[i]);
				count++;
			}
		}
		return pwd.toString();
	}

	
	
	public static long getLong() {
		return Long.parseLong(getString());
	}
	public static String getString() {
		// 声明一个种子
		int seed[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
		// 存放生成后的数字
		StringBuffer destArray = new StringBuffer(seed.length);
		// 声明一个Random实例
		Random random = new Random();
		// 循环种子
		for (int i = 0; i < seed.length; i++) {
			// 随机得到种子中的一个位置
			int j = random.nextInt(seed.length - i);
			// 把该位置上的种子输出
			destArray.append(seed[j]);
			// 把种子中末尾的种子替换得到的种子
			seed[j] = seed[seed.length - 1 - i];
		}
		return destArray.toString();
	}

	/***
	 * 获取第二天
	 * 
	 * @param curDate
	 * @return
	 */
	public static Date getNextDate(Date curDate) {
		Calendar cal = Calendar.getInstance();
		cal.setTimeInMillis(curDate.getTime() + 24 * 60 * 60 * 1000);
		return cal.getTime();
	}

	/**
	 * 初始化的时候定时器默认开启
	 */
	public static boolean clock = false;

}